Re: [PATCH] staging: rtl8712: check register_netdev() return value

[Dan Carpenter]

On Wed, Dec 09, 2020 at 11:01:24PM +0800, shaojie.dong@xxxxxxxxxxxxxxxx wrote:
> From: "shaojie.dong" <shaojie.dong@xxxxxxxxxxxxxxxx>
> 
> Function register_netdev() can fail, so we should check it's return value
> 
> Signed-off-by: shaojie.dong <shaojie.dong@xxxxxxxxxxxxxxxx>
> ---
>  drivers/staging/rtl8712/hal_init.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rtl8712/hal_init.c b/drivers/staging/rtl8712/hal_init.c
> index 715f1fe8b..38a3e3d44 100644
> --- a/drivers/staging/rtl8712/hal_init.c
> +++ b/drivers/staging/rtl8712/hal_init.c
> @@ -45,7 +45,10 @@ static void rtl871x_load_fw_cb(const struct firmware *firmware, void *context)
>  	}
>  	adapter->fw = firmware;
>  	/* firmware available - start netdev */
> -	register_netdev(adapter->pnetdev);
> +	if (register_netdev(adapter->pnetdev) != 0) {
> +		netdev_err(adapter->pnetdev, "register_netdev() failed\n");
> +		free_netdev(adapter->pnetdev);
> +	}

This function should not be calling register_netdev().  What does that
have to do with firmware?  It should also not free_netdev() because
that will just lead to a use after free in the caller.

regards,
dan carpenter

>  	complete(&adapter->rtl8712_fw_ready);
>  }
>  
> -- 
> 2.17.1
> 
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